Swear words, or bad language, make up about 0.6% of our spoken language. Given that we speak an average of about 16,000 words each day, this means that about 95 of our daily words are profanities. In general, swear words are intended to be offensive – but in one situation they can be helpful.

Bad words 101 Perhaps we swear precisely because we are told not to? The word profane comes from the Latin roots pro meaning before and fanum meaning temple. So a profanity was something that you said only before the temple – or, in today’s language, outside it. A profanity was definitely not to be spoken inside the temple. Cursing is universal. Profanities exist in every language, dialect or patois ever studied. They all have forbidden or bad words – regardless of whether that language is living or dead, is spoken by billions or a small tribe. Interestingly, some cultures draw their swear words from religion. For example, when Shakespeare wrote zounds or ’sblood four centuries ago, he was using offensive (for the day) contractions of the phrases “God’s wounds” (zounds), and “God’s blood” (’sblood). Other societies fiercely protect the concept of the honour and “purity” of women. So, many of their swear words relate either to female genitalia, or to the theme “son of a whore”.

Power words Swear words have power and can change the human body. Merely hearing profanities will alter the electrical conductance of your skin, quicken your pulse, make the hairs on your arms rise and your breathing more shallow. The power of swear words can change over time as our language evolves. For instance nobody today would be bothered by the word golly, which originally was an obscene and profane contraction of the phrase “God’s body”. And sometimes words once considered neutral can become a little unpleasant or uncomfortable to use. For example, the word coffin originally meant a box. But once the word coffin became linked to the concept of death, people stopped saying “Let’s think outside the coffin”, or “Let’s see if there’s anything to eat in the bread coffin”. I think that’s a gosh darn shame.

Set up the study Back in 2009, Richard Stephens and colleagues from Keele University in the UK looked at the link between swearing and pain. Many people swear when they suffer an injury and suddenly feel pain. The scientists asked: does the swearing relieve the pain, make the pain worse, or have no effect on the pain? Sixty-seven unfortunate undergraduate students endured the cold pressor test which involved submerging their unclenched and nondominant hand into cold water (5°C), for as long as they could stand it. While their hand was in the cold water the students were instructed to say, over and over, either a swear word or a neutral (control) word. The swear words were chosen by asking the students for “five words you might use after hitting yourself on the thumb with a hammer”. The experimenters chose the first swear word on each person’s list to be their naughty word. Why have a control word? The experimenters needed to control for the possibility that simply saying any word could change how long the subjects would be able to keep their hand in cold water. So they also asked the students for five words to describe a table – for example, bench, counter, desk, worktable, horizontal surface and so on. One of those words became the control word.

Results – time and heart rate The study showed that while repeating the control word, men on average could withstand the cold water for 146 seconds, but women could go for 83 seconds. If they repeated their chosen profanity, each gender could keep their hand in the cold water for an extra 40 seconds on average. A similar pattern was found for the heart rate. Comparing men and women, in each case the men had a lower heart rate before the cold pressor test, with the cold pressor test and the control word, and with the cold pressor test and the swear word. The pulse of both sexes was lowest before the cold pressor test. It rose slightly when they had their hand in cold water and were saying a neutral word, but rose even higher when they were saying their preferred profanity. The increase in the heart rate was approximately the same for each sex. This was probably related to the release of adrenaline – but no blood samples were taken to test these levels. So, according to this study, swearing makes pain “go away” or become more “bearable” – because the subjects could keep their hand in cold water for longer.

The power to change pain For better or worse, swear words are more common nowadays than in the recent past. After all, we use swear words to express surprise and happiness, or anger and disgust. But what about people who tend to swear more than average? Does the power of profanity fade the more you use it? In 2011, Stephens did a follow-up to see “if overuse of swearing in everyday situations lessens its effectiveness as a short-term intervention to reduce pain”. The answer was yes. The more the subjects swore on a daily basis, the less extra time they could withstand cold water while swearing. So if you’re prone to cuss and curse, you would get less pain relief by swearing. Here is the lesson for the day: it’s OK to be profane, but only when you’re in pain. CREDIT: EDITED EXTRACT FROM HOUSE OF KARLS, MACMILLAN 2014

This article appeared in Cosmos 65 - Oct-Nov 2015 under the headline "Why do we swear?"